<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <style>

        .box{

             width: 100px;
            height: 100px;
            border: 5px solid;
            background-color: red !important;
        }

        div{
            background-color: greenyellow;
        }

        #test{
            background-color: red;
        }
    </style>
    <link rel="stylesheet" href="../../css/style.css">
</head>
<body>
<div class=" box2 box" >

</div>

<div class="box2">

</div>
<div>
    ddd
</div>

<div style="background-color: green">
    test
</div>
</body>
</html>